The National Highway Traffic Safety Administration (NHTSA) has closed their investigation into engine problems in the 2011-13 F-150 after Ford sent a technical service bulletin to dealers on how to fix the problem.
NHTSA had received 95 complaints about the 3.5L EcoBoost engine in F-150 trucks misfiring. The misfires would only happen under humid or rainy conditions.
The EcoBoost engine uses twin turbochargers that compress air to increase the engine's power, and what Ford found was condensation building up inside of the air cooler tubes. When the condensation is high enough, up to three cylinders can misfire.…keep reading article "Engine Investigation Closed for the 2011-2013 F-150"